On Fri, 2016-06-24 at 07:25 -0700, Eric Dumazet wrote:
> Please do not top post on netdev mailing list
>
> On Fri, Jun 24, 2016 at 4:38 AM, Arjun V. <[email protected]> wrote:
> > Eric,
> > We are seeing skb's with length(skb->len) greater than 65536 coming into
> > our ndo_start_xmit() callback routine.
> > We can add a check in our eth_xmit() routine to skip those packets, but it
> > will be better if you fix this in kernel.
> >
> >
> > I have attached pcap file obtained from tcpdump. In the pcap file there are
> > 2 such packets(I used tcpdump filter to extract out those packets).
> >
> > Let us know if you need anything else.
> >
>
> Beats me really.
>
> At retransmit time, we only can eventually reduce packet sizes
> (assuming GSO is used, because we might coalesce sub-mss packets in
> tcp_retrans_try_collapse())
>
> So why are you seeing too big packets at retransmit, I really have no idea.
>
> MIght be some bug related to MSS computation, overflowing somehow ?
Could you try this ?
Thanks !
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index
d39e9e47a26e55ad2b8f775bf9ea9dfb5b12aee5..27013056bcfb9aa49601806bb3aa55a1ac664873
100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1177,6 +1177,7 @@ int inet_sk_rebuild_header(struct sock *sk)
/* Routing failed... */
sk->sk_route_caps = 0;
+ sk->sk_gso_max_segs = 1;
/*
* Other protocols have to map its equivalent state to
TCP_SYN_SENT.
* DCCP maps its DCCP_REQUESTING state to TCP_SYN_SENT. -acme
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index
2076c21107d07e4e78a0a29f1d374c3414b8e1bd..ecc0281acfb702b138c68ac51e3a0518052785b0
100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -685,6 +685,7 @@ int inet6_sk_rebuild_header(struct sock *sk)
dst = ip6_dst_lookup_flow(sk, &fl6, final_p);
if (IS_ERR(dst)) {
sk->sk_route_caps = 0;
+ sk->sk_gso_max_segs = 1;
sk->sk_err_soft = -PTR_ERR(dst);
return PTR_ERR(dst);
}
